Joint determination of demodulation and channel state information reference signals

ABSTRACT

The described techniques provide for mapping one or more demodulation reference signal (DMRS) patterns to one or more available channel state information reference signal (CSI-RS) resources. A UE receiving DMRS and CSI-RS signals may determine CSI-RS resources, or reduce its search space for identification of CSI-RS transmissions, based on a DMRS pattern for a transmission. In some cases, a base station may transmit DMRS patterns and a mapping between DMRS patterns and CSI-RS resources to a UE. CSI-RS resources may be configured semi-statically or dynamically by a base station. In some cases, one or more null DMRS patterns may be configured and mapped to CSI-RS resources, and a base station may use a null DMRS pattern for one UE to transmit a DMRS to a different UE, and both UEs may measure channel state information based on an associated CSI-RS transmitted in mapped CSI-RS resources.

CROSS REFERENCES

The present Application for Patent claims priority to Greece PatentApplication No. 2017/0100370 by Manolakos, et al., entitled “JointDetermination of Demodulation and Channel State Information ReferenceSignals,” filed Aug. 4, 2017, assigned to the assignee hereof, andexpressly incorporated herein.

BACKGROUND

The following relates generally to wireless communication and to jointdetermination of demodulation and channel state information referencesignals.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such as aLong Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, andfifth generation (5G) systems which may be referred to as New Radio (NR)systems. These systems may employ technologies such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal frequency division multipleaccess (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM).A wireless multiple-access communications system may include a number ofbase stations or network access nodes, each simultaneously supportingcommunication for multiple communication devices, which may be otherwiseknown as user equipment (UE).

SUMMARY

The described techniques relate to improved methods, systems, devices,or apparatuses that support joint determination of demodulation andchannel state information reference signals. Generally, the describedtechniques provide for mapping one or more demodulation reference signal(DMRS) patterns to one or more available channel state informationreference signal (CSI-RS) resources. A UE receiving DMRS and CSI-RSsignals may thus determine CSI-RS resource or reduce its search spacefor identification of CSI-RS transmissions based on a DMRS pattern for atransmission. In some cases, a base station may transmit DMRS patternsand a mapping between DMRS patterns and CSI-RS resources to a userequipment (UE). CSI-RS resources may be configured semi-statically ordynamically by a base station. In some cases, one or more null DMRSpatterns may be configured and mapped to CSI-RS resources, and a basestation may use a null DMRS pattern for one UE to transmit a DMRS to adifferent UE, and both UEs may measure channel state information basedon an associated CSI-RS transmitted in mapped CSI-RS resources. In someother cases, one or more DMRS patterns may be precluded for DMRStransmissions, based in part on a CSI-RS configuration. In such cases,the mapping between the DMRS patterns and CSI-RS resources may indicatethe constraints on DMRS.

A method of wireless communication is described. The method may includeidentifying a set of DMRS patterns for use at a UE and a set ofavailable CSI-RS resources, receiving DCI indicating one or more of theDMRS patterns based on a mapping between one or more of the set of DMRSpatterns and one or more of the set of available CSI-RS resources thatare associated with the one or more DMRS patterns, and receiving one ormore of a DMRS or a CSI-RS based on the received DCI and the mapping.

An apparatus for wireless communication is described. The apparatus mayinclude a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe executable by the processor to cause the apparatus to identify a setof DMRS patterns for use at a UE and a set of available CSI-RSresources, receive DCI indicating one or more of the DMRS patterns basedon a mapping between one or more of the set of DMRS patterns and one ormore of the set of available CSI-RS resources that are associated withthe one or more DMRS patterns, and receive one or more of a DMRS or aCSI-RS based on the received DCI and the mapping.

Another apparatus for wireless communication is described. The apparatusmay include means for identifying a set of DMRS patterns for use at a UEand a set of available CSI-RS resources, receiving DCI indicating one ormore of the DMRS patterns based on a mapping between one or more of theset of DMRS patterns and one or more of the set of available CSI-RSresources that are associated with the one or more DMRS patterns, andreceiving one or more of a DMRS or a CSI-RS based on the received DCIand the mapping.

A non-transitory computer-readable medium storing code for wirelesscommunication is described. The code may include instructions executableby a processor to identify a set of DMRS patterns for use at a UE and aset of available CSI-RS resources, receive DCI indicating one or more ofthe DMRS patterns based on a mapping between one or more of the set ofDMRS patterns and one or more of the set of available CSI-RS resourcesthat are associated with the one or more DMRS patterns, and receive oneor more of a DMRS or a CSI-RS based on the received DCI and the mapping.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving an indicationof a first DMRS pattern for a first downlink transmission, identifying afirst subset of CSI-RS resources that may be mapped to the first DMRSpattern and determining first CSI-RS resources associated with the firstdownlink transmission based on the first subset of CSI-RS resources.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the determining the firstCSI-RS resources may include operations, features, means, orinstructions for receiving an indication of the first CSI-RS resourceswithin the first subset of CSI-RS resources in control informationassociated with the first downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the indication of the firstCSI-RS resources may be received dynamically in DCI associated with thefirst downlink transmission.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for semi-staticallyreceiving configuration information including the set of DMRS patternsand the set of available CSI-RS resources.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the configuration informationmay be received in RRC signaling.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of DMRS patternsincludes a null DMRS pattern mapped to one or more CSI-RS resources.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the receiving the one or moreof the DMRS or CSI-RS may include operations, features, means, orinstructions for receiving a CSI-RS in a downlink transmission over theone or more CSI-RS resources mapped to the null DMRS pattern, and wherea DMRS may be not received in the downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of DMRS patternsincludes a set of null DMRS patterns.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of null DMRS patternsmay be received in a cell-specific configuration of all UEs within acell.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving an indicationof one or more zero power (ZP) CSI-RS resources that may be configuredindependently of the DMRS patterns.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining aconfiguration of the CSI-RS based on an associated DMRS pattern anddetermining frequency resources of the CSI-RS based on associated DMRSfrequency resources.

A method of wireless communication is described. The method may includeidentifying a set of DMRS patterns for a UE and a set of availableCSI-RS resources for the UE, determining a mapping between one or moreof the DMRS patterns and one or more of the set of available CSI-RSresources, transmitting DCI indicating one or more of the DMRS patternsbased on the determined mapping, and transmitting one or more of a DMRSor CSI-RS based on the transmitted DCI and the determined mapping.

An apparatus for wireless communication is described. The apparatus mayinclude a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe executable by the processor to cause the apparatus to identify a setof DMRS patterns for a UE and a set of available CSI-RS resources forthe UE, determine a mapping between one or more of the DMRS patterns andone or more of the set of available CSI-RS resources, transmit DCIindicating one or more of the DMRS patterns based on the determinedmapping, and transmit one or more of a DMRS or CSI-RS based on thetransmitted DCI and the determined mapping.

Another apparatus for wireless communication is described. The apparatusmay include means for identifying a set of DMRS patterns for a UE and aset of available CSI-RS resources for the UE, determining a mappingbetween one or more of the DMRS patterns and one or more of the set ofavailable CSI-RS resources, transmitting DCI indicating one or more ofthe DMRS patterns based on the determined mapping, and transmitting oneor more of a DMRS or CSI-RS based on the transmitted DCI and thedetermined mapping.

A non-transitory computer-readable medium storing code for wirelesscommunication is described. The code may include instructions executableby a processor to identify a set of DMRS patterns for a UE and a set ofavailable CSI-RS resources for the UE, determine a mapping between oneor more of the DMRS patterns and one or more of the set of availableCSI-RS resources, transmit DCI indicating one or more of the DMRSpatterns based on the determined mapping, and transmit one or more of aDMRS or CSI-RS based on the transmitted DCI and the determined mapping.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting anindication of a first DMRS pattern for a first downlink transmission,identifying a first subset of CSI-RS resources that may be mapped to thefirst DMRS pattern, selecting a first CSI-RS resource based on the firstsubset of CSI-RS resources that may be mapped to the first DMRS patternand transmitting an indication of the first CSI-RS resource.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the indication of the firstCSI-RS resource may be transmitted dynamically in DCI associated withthe first downlink transmission.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for semi-staticallytransmitting in RRC signaling configuration information including theset of DMRS patterns and the set of available CSI-RS resources.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of DMRS patternsincludes a null DMRS pattern mapped to one or more CSI-RS resources.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting a CSI-RSin a downlink transmission over the one or more CSI-RS resources mappedto the null DMRS pattern, and where a DMRS may be not transmitted in thedownlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of DMRS patternsincludes a set of null DMRS patterns that may be configured at a set ofUEs in a cell-specific configuration.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for configuring one or morezero power (ZP) CSI-RS resources at the UE independently of the DMRSpatterns.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining aconfiguration of the CSI-RS based on an associated DMRS pattern anddetermining frequency resources of the CSI-RS based on associated DMRSfrequency resources.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communicationthat supports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure.

FIG. 2 illustrates an example of a wireless communication system thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure.

FIG. 3 illustrates examples of DMRS patterns that support jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure.

FIG. 4 illustrates other examples of DMRS patterns that support jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure.

FIG. 5 illustrates examples of different resource configurations thatsupport joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure.

FIG. 6 illustrates further examples of resource configurations thatsupport joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure.

FIG. 7 illustrates an example of a mapping that supports jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure.

FIG. 8 illustrates an example of CSI-RS settings, resource sets, andassociated resources that support joint determination of demodulationand channel state information reference signals in accordance withaspects of the present disclosure.

FIG. 9 illustrates an example of DMRS and CSI-RS resources in accordancewith aspects of the present disclosure.

FIG. 10 illustrates examples of DMRS and CSI-RS resources with andwithout frequency domain staggering that support joint determination ofdemodulation and channel state information reference signals inaccordance with aspects of the present disclosure.

FIG. 11 illustrates an example of a process flow that supports jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure.

FIGS. 12 through 14 show block diagrams of a device that supports jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure.

FIG. 15 illustrates a block diagram of a system including a UE thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure.

FIGS. 16 through 18 show block diagrams of a device that supports jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure.

FIG. 19 illustrates a block diagram of a system including a base stationthat supports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure.

FIGS. 20 through 23 illustrate methods for joint determination ofdemodulation and channel state information reference signals inaccordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communication systems, a transmitter may transmit ademodulation reference signal (DMRS) that a receiver may use todemodulate other transmissions from the transmitter. In some systems,such DMRS transmissions may be transmitted using specified resourcesavailable for transmission (e.g., in a middle symbol of a transmissionslot). In some next generation wireless communication systems (e.g., a5G or NR system), various different DMRS patterns may be used for DMRStransmissions, in which different resources (i.e., DMRS resourceelements) may be used within a wireless subframe or slot. In such cases,a base station may configure a particular DMRS pattern or DMRS patternsfor data demodulation, which in some cases may support a front-loadedDMRS pattern in which a DMRS transmission is located relatively early ina transmission (e.g., in a first symbol following a control informationsymbol). Such variable or configurable resources for DMRS transmissionsmay have an impact on other reference signals, such as a channel stateinformation reference signal (CSI-RS). Thus, a receiver such as a userequipment (UE), may need to be aware of both a DMRS configuration and aCSI-RS configuration in order to properly receive one or both referencesignals.

Various techniques discussed herein provide for mapping one or more DMRSpatterns to one or more available CSI-RS resources. A UE receiving DMRSand CSI-RS signals may thus determine CSI-RS resources, or reduce asearch space for identification of CSI-RS transmissions, based on a DMRSpattern. In some cases, a base station may transmit DMRS patterns and amapping between DMRS patterns and CSI-RS resources to a user equipment(UE). The base station may then transmit (e.g., in downlink controlinformation (DCI) or radio resource control (RRC) signaling) anindication of a DMRS pattern and an indication of a selected CSI-RSresource (e.g., an index to a set of CSI-RS resources provided in themapping) used for one or more transmissions. A UE may use the DMRSpattern, the indication of the selected CSI-RS resource, and themapping, to determine CSI-RS resources. In some instances, instead of orin addition to an explicit mapping from the base station, the UE maydetermine an implicit mapping between the DMRS pattern transmitted bythe base station and the CSI-RS resources. In some instances, forexample, the UE may determine, based on a grant, the DMRS pattern thatis to be transmitted and may implicitly determine which configuredCSI-RS resources cannot also be transmitted. In certain instances, theUE may receive the implicit mapping through other signaling.Accordingly, there may be an implicit association between the DMRS andCSI-RS resources.

In some other cases, the base station may transmit a CSI-RS resourceconfiguration, and a mapping between DMRS patterns and CSI-RS resourcesto a UE. In such cases, one or more DMRS patterns may be precluded fromDMRS transmissions based in part on the CSI-RS configuration. Thus, DMRSand CSI-RS transmissions may be configured semi-statically ordynamically by a base station. In some cases, one or more null DMRSpatterns may be configured and mapped to one or more CSI-RS resources,and a base station may use a null DMRS pattern for one UE to transmit aDMRS to a different UE, and both UEs may measure channel stateinformation based on an associated CSI-RS transmitted in mapped CSI-RSresources.

Aspects of the disclosure are initially described in the context of awireless communications system. Various examples of DMRS patterns,CSI-RS resources, and mappings between DMRS patterns and CSI-RSresources are then described. Aspects of the disclosure are furtherillustrated by and described with reference to apparatus diagrams,system diagrams, and flowcharts that relate to joint determination ofdemodulation and channel state information reference signals.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A)network, or a New Radio (NR) network. In some cases, wirelesscommunications system 100 may support enhanced broadband communications,ultra-reliable (e.g., mission critical) communications, low latencycommunications, or communications with low-cost and low-complexitydevices. UEs 115 and base stations 105 may transmit one or morereference signals, in which resources of one reference signal may bemapped to another reference signal to allow joint determination ofresources for both reference signals.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation Node B orgiga-nodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. Wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in wirelesscommunications system 100 may include uplink transmissions from a UE 115to a base station 105, or downlink transmissions, from a base station105 to a UE 115. Downlink transmissions may also be called forward linktransmissions while uplink transmissions may also be called reverse linktransmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, eachbase station 105 may provide communication coverage for a macro cell, asmall cell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable andtherefore provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap, and overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A or NR network in which different types of basestations 105 provide coverage for various geographic coverage areas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone, a personal digital assistant(PDA), a tablet computer, a laptop computer, or a personal computer. Insome examples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet of Things (IoT) device, an Internet of Everything(IoE) device, or an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles, meters, or the like.

In some cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105, or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 facilitates the scheduling ofresources for D2D communications. In other cases, D2D communications arecarried out between UEs 115 without the involvement of a base station105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an S1 or otherinterface). Base stations 105 may communicate with one another overbackhaul links 134 (e.g., via an X2 or other interface) either directly(e.g., directly between base stations 105) or indirectly (e.g., via corenetwork 130).

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

Wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 MHz to 300 GHz.Generally, the region from 300 MHz to 3 GHz is known as the ultra-highfrequency (UHF) region or decimeter band, since the wavelengths rangefrom approximately one decimeter to one meter in length. UHF waves maybe blocked or redirected by buildings and environmental features.However, the waves may penetrate structures sufficiently for a macrocell to provide service to UEs 115 located indoors. Transmission of UHFwaves may be associated with smaller antennas and shorter range (e.g.,less than 100 km) compared to transmission using the smaller frequenciesand longer waves of the high frequency (HF) or very high frequency (VHF)portion of the spectrum below 300 MHz.

Wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that can tolerate interference from otherusers.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ License Assisted Access(LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technologyin an unlicensed band such as the 5 GHz ISM band. When operating inunlicensed radio frequency spectrum bands, wireless devices such as basestations 105 and UEs 115 may employ listen-before-talk (LBT) proceduresto ensure a frequency channel is clear before transmitting data. In somecases, operations in unlicensed bands may be based on a CA configurationin conjunction with CCs operating in a licensed band (e.g., LAA).Operations in unlicensed spectrum may include downlink transmissions,uplink transmissions, peer-to-peer transmissions, or a combination ofthese. Duplexing in unlicensed spectrum may be based on frequencydivision duplexing (FDD), time division duplexing (TDD), or acombination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, wirelesscommunication system may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving devices are equipped with one ormore antennas. MIMO communications may employ multipath signalpropagation to increase the spectral efficiency by transmitting orreceiving multiple signals via different spatial layers, which may bereferred to as spatial multiplexing. The multiple signals may, forexample, be transmitted by the transmitting device via differentantennas or different combinations of antennas. Likewise, the multiplesignals may be received by the receiving device via different antennasor different combinations of antennas. Each of the multiple signals maybe referred to as a separate spatial stream, and may carry bitsassociated with the same data stream (e.g., the same codeword) ordifferent data streams. Different spatial layers may be associated withdifferent antenna ports used for channel measurement and reporting. MIMOtechniques include single-user MIMO (SU-MIMO) where multiple spatiallayers are transmitted to the same receiving device, and multiple-userMIMO (MU-MIMO) where multiple spatial layers are transmitted to multipledevices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g. synchronization signals,reference signals, beam selection signals, or other control signals) maybe transmitted by a base station 105 multiple times in differentdirections, which may include a signal being transmitted according todifferent beamforming weight sets associated with different directionsof transmission. Transmissions in different beam directions may be usedto identify (e.g., by the base station 105 or a receiving device, suchas a UE 115) a beam direction for subsequent transmission and/orreception by the base station 105. Some signals, such as data signalsassociated with a particular receiving device, may be transmitted by abase station 105 in a single beam direction (e.g., a directionassociated with the receiving device, such as a UE 115). In someexamples, the beam direction associated with transmissions along asingle beam direction may be determined based at least in in part on asignal that was transmitted in different beam directions. For example, aUE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions, and the UE 115 may report to thebase station 105 an indication of the signal it received with a highestsignal quality (e.g., based on measurements of one or more referencesignals such as a CSI-RS), or an otherwise acceptable signal quality.Although these techniques are described with reference to signalstransmitted in one or more directions by a base station 105, a UE 115may employ similar techniques for transmitting signals multiple times indifferent directions (e.g., for identifying a beam direction forsubsequent transmission or reception by the UE 115), or transmitting asignal in a single direction (e.g., for transmitting data to a receivingdevice).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples, areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based at least inpart on listening according to different receive beam directions (e.g.,a beam direction determined to have a highest signal strength, highestsignal-to-noise ratio, or otherwise acceptable signal quality based atleast in part on listening according to multiple beam directions).

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period ofT_(s)=1/30,720,000 seconds. Time intervals of a communications resourcemay be organized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases, a subframe may be thesmallest scheduling unit of the wireless communications system 100, andmay be referred to as a transmission time interval (TTI). In othercases, a smallest scheduling unit of the wireless communications system100 may be shorter than a subframe (e.g., a slot TTI) or may bedynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or inselected component carriers using sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot, or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots, or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resourceshaving a defined physical layer structure for supporting communicationsover a communication link 125. For example, a carrier of a communicationlink 125 may include a portion of a radio frequency spectrum band thatis operated according to physical layer channels for a given radioaccess technology. Each physical layer channel may carry user data,control information, or other signaling. A carrier may be associatedwith a pre-defined frequency channel (e.g., an E-UTRA absolute radiofrequency channel number (EARFCN)), and may be positioned according to achannel raster for discovery by UEs 115. Carriers may be downlink oruplink (e.g., in an FDD mode), or be configured to carry downlink anduplink communications (e.g., in a TDD mode). In some examples, signalwaveforms transmitted over a carrier may be made up of multiplesub-carriers (e.g., using multi-carrier modulation (MCM) techniques suchas OFDM or DFT-s-OFDM).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, NR, etc.). Forexample, communications over a carrier may be organized according toTTIs or slots, each of which may include user data as well as controlinformation or signaling to support decoding the user data. A carriermay also include dedicated acquisition signaling (e.g., synchronizationsignals or system information, etc.), and control signaling thatcoordinates operation for the carrier. In some examples (e.g., in acarrier aggregation configuration), a carrier may also have acquisitionsignaling or control signaling that coordinates operations for othercarriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space and one or more UE-specificcontrol regions or UE-specific search spaces).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

As indicated above, in some cases, a transmitter such as a base station105, may transmit a DMRS that may be used by a receiver, such as a UE115, for channel estimation and coherent demodulation of datatransmissions from the transmitter. Also, as indicated above, in somecases wireless resources for DMRS transmissions may be variable orconfigurable, and various different DMRS patterns may be employeddepending upon the type and configuration of transmissions. The variableDMRS patterns may also impact resources used for other transmissions,such as CSI-RS transmissions, and various techniques discussed hereinprovide for mapping one or more DMRS patterns to one or more availableCSI-RS resources. A UE receiving DMRS and CSI-RS signals may thusdetermine CSI-RS resources, or reduce a search space for identificationof CSI-RS transmissions, based on a DMRS pattern. In some other cases,the available DMRS patterns from a set of DMRS patterns may beconstrained based in part on a CSI-RS configuration. For example, one ormore DMRS patterns from the set of DMRS patterns may be precluded forDMRS transmissions based on CSI-RS configured at the base station. Thus,the UE may utilize an implicit mapping scheme where the UE mayimplicitly determine which configured CSI-RS resources or DMRS patternscannot also be transmitted based on the DMRS pattern or CSI-RSconfiguration, respectively.

FIG. 2 illustrates an example of a wireless communication system 200that supports joint determination of demodulation and channel stateinformation reference signals in accordance with various aspects of thepresent disclosure. In some examples, wireless communication system 200may implement aspects of wireless communication system 100. Wirelesscommunication system 200 may include a base station 105-a and a UE115-a, which may be examples of the corresponding devices described withreference to FIG. 1.

In some examples, base station 105-a may be in communication with one ormore UEs 115 within geographic coverage area 205. For example, basestation 105-a may be in communication with UE 115-a via bidirectionalcommunication link 210. Base station 105-a may transmit one or morereference signals, such as a DMRS 215 or a CSI-RS 220. In some cases,DMRS 215 may be transmitted using wireless resources at differentlocations within a transmission slot, and resources used for CSI-RS 220may be modified based on the DMRS 215 resources. In some cases, forexample, DMRS 215 may be transmitted in up to four OFDM symbols within asubframe, and a location of the DMRS 215 symbols may be different indifferent subframes. In some cases, CSI-RS 220 may not be multiplexed onany of the potential DMRS 215 OFDM symbol(s). However, in such cases,the locations of CSI-RS 220 may be relatively limited. In other cases,if DMRS 215 may be transmitted on a first number of symbols (e.g., up tofour symbols), but is not transmitted on a subset of those symbols(e.g., DMRS is transmitted on only two symbols), CSI-RS 220 may betransmitted on the subset of the first number of symbols. In furthercases, CSI-RS 220 may be multiplexed on all potential DMRS 215 OFDMsymbol(s). As indicated above, various aspects of the present disclosureprovide mappings between CSI-RS 220 resources and patterns of DMRS 215transmissions. Thus, the CSI-RS 220 resources for a particulartransmission or set of transmissions may be determined based on the DMRS215 for that transmission or set of transmissions. In some cases, CSI-RS220 resources may span 1, 2, or 4 OFDM symbols. If CSI-RS 220 resourcesspan four OFDM symbols, for example, two pairs of adjacent OFDM symbolsmay be used for one CSI-RS 220 resource, where the two pairs can beadjacent or non-adjacent.

In some other cases, DMRS 215 may be constrained based on the configuredCSI-RS 220. For instance, base station 105-a may transmit a mappingbetween CSI-RS 220 and DMRS 215, along with a CSI-RS configuration(i.e., potential CSI-RS 220 OFDM symbol(s)). In such cases, one or moreDMRS patterns may be precluded for DMRS 215 transmissions.

FIGS. 3 through 6 illustrate several examples of potential DMRSpatterns.

FIG. 3 illustrates examples of DMRS patterns 300 that support jointdetermination of demodulation and channel state information referencesignals in accordance with various aspects of the present disclosure. Insome examples, DMRS patterns 300 may implement aspects of wirelesscommunication system 100 or 200. In this example, a UE (e.g., a UE 115of FIG. 1 or FIG. 2), may be configured by higher layers with DMRSpattern either from a front-loaded DMRS Configuration type 1, or from afront-loaded DMRS Configuration type 2 for downlink and uplinktransmissions. DMRS patterns 300 illustrate example configuration type 1patterns. In some aspects, a DMRS pattern may refer to one or moreresource elements used for DMRS transmissions, DMRS resource elements,which may be located in certain time-frequency locations within a frame,subframe, slot, or other time interval according to a configuration bythe network or base station. Such DMRS patterns may repeat at regularintervals for a slot, subframe, frame, or a number of frames, or anothertime interval.

In the examples of FIG. 3, a first DMRS pattern 305 and a second DMRSpattern 310 are one-symbol DMRS patterns that are front loaded in afirst slot of a subframe. The one-symbol patterns may be used for DMRStransmissions on up to four antenna ports, with the first DMRS patternproviding DMRS for antenna ports 0 and 1, and the second DMRS patternproviding DMRS for antenna ports 2 and 3. The one-symbol DMRS patternsmay use a comb pattern with every other tone having a DMRS for adifferent antenna port.

DMRS patterns 300 may also include two-symbol DMRS patterns that includea third DMRS pattern 315, a fourth DMRS pattern 320, a fifth DMRSpattern 325, and a sixth DMRS pattern 330, in which DMRS for up to eightantenna ports may be provided. In the illustrated example DMRS patterns315 through 330, a comb pattern may be used along with a time domainorthogonal cover code (TD-OCC) (e.g., {1 1} and {1 −1} for adjacentsymbols), and may provide DMRS for up to 8 antenna ports. In otherexamples, DMRS patterns may be used that provide DMRS for up to fourantenna ports without using both TD-OCC {1,1} and {1,−1}.

FIG. 4 illustrates examples of DMRS patterns 400 that support jointdetermination of demodulation and channel state information referencesignals in accordance with various aspects of the present disclosure. Insome examples, DMRS patterns 400 may implement aspects of wirelesscommunication system 100 or 200. In this example, a UE (e.g., a UE 115of FIG. 1 or FIG. 2), may again be configured from a front-loaded DMRSConfiguration type 1 or from a front-loaded DMRS Configuration type 2for downlink and uplink transmissions. DMRS patterns 400 illustrateexample configuration type 2 patterns.

In the examples of FIG. 4, a first DMRS pattern 405 and a second DMRSpattern 410 are one-symbol DMRS patterns that are front loaded in afirst slot of a subframe. The one-symbol patterns may be used for DMRStransmissions on up to six antenna ports, with the first DMRS pattern405 providing DMRS for antenna ports 0, 1, and 2, and the second DMRSpattern 410 providing DMRS for antenna ports 3, 4, and 5. The one-symbolDMRS patterns may use a frequency division (FD) OCC (e.g., {1 1} and {1−1}) for adjacent REs in the frequency domain, to provide DMRS for up to6 antenna ports.

DMRS patterns 400 may also include two-symbol DMRS patterns that includea third DMRS pattern 415, a fourth DMRS pattern 420, a fifth DMRSpattern 425, and a sixth DMRS pattern 430, in which DMRS for up to 12antenna ports may be provided. In the illustrated example DMRS patterns415 through 430, FD-OCC may be applied across adjacent REs in thefrequency domain, and TD-OCC (e.g., {1,1} and {1,−1}) applied acrossadjacent REs in the time domain. The DMRS signal sequence design fordownlink and uplink CP-OFDM is a known QPSK sequence that is transmittedby each port in the corresponding resource elements.

FIG. 5 illustrates further examples of DMRS patterns 500 that supportjoint determination of demodulation and channel state informationreference signals in accordance with various aspects of the presentdisclosure. In some examples, DMRS patterns 500 may implement aspects ofwireless communication system 100 or 200. In this example, somesubframes may include both a downlink portion and an uplink burstportion, and some subframes may include only downlink transmissions.Depending upon which symbols are configured for downlink or uplinktransmissions, other symbols may be configured for DMRS to provideenhanced DMRS for each subframe.

In the examples of FIG. 5, a number of DMRS patterns may be used forsubframes with no uplink burst portions, including first DMRS pattern505 with four spaced DMRS symbols, a second DMRS pattern 510 with threespaced DMRS symbols, a third DMRS pattern 515 with two spaced DMRSsymbols, and a fourth DMRS pattern 520 with four DMRS symbols that arelocated in pairs of symbols, with different pairs spread across thesubframe. In cases where a two-symbol uplink burst is present, a fifthDMRS pattern 525 may include three spaced DMRS symbols, a sixth DMRSpattern 530 with two spaced DMRS symbols, and a seventh DMRS pattern 535with two front-loaded DMRS symbols and a third spaced DMRS symbol.

In cases where a three-symbol uplink burst is present, an eighth DMRSpattern 540 may include three spaces DMRS symbols, a ninth DMRS pattern545 may include two spaced DMRS symbols, and a tenth DMRS pattern 550may include four DMRS symbols arranged as pairs of adjacent DMRS symbolswith different pairs spread across the downlink symbols. In cases wherea five-symbol uplink burst is present, an eleventh DMRS pattern 555 mayhave two spaced DMRS symbols spread across the downlink symbols.

FIG. 6 illustrates further examples of DMRS patterns 600 that supportjoint determination of demodulation and channel state informationreference signals in accordance with various aspects of the presentdisclosure. In some examples, DMRS patterns 600 may implement aspects ofwireless communication system 100 or 200. In this example again, somesubframes may include both a downlink portion and an uplink burstportion, and some subframes may include only downlink transmissions.Depending upon which symbols are configured for downlink or uplinktransmissions, other symbols may be configured for DMRS to provideenhanced DMRS for each subframe. In the examples of FIG. 6, DMRS symbolsmay be located at the same symbols within a subframe irrespective of anumber of uplink symbols, with uplink symbols replacing DMRS symbols inthe event that the DMRS symbol is located in the uplink burst.

In the examples of FIG. 6, a number of DMRS patterns may be used forsubframes with no uplink burst portions, including first DMRS pattern605 with four spaced DMRS symbols, a second DMRS pattern 610 with threespaced DMRS symbols, a third DMRS pattern 615 with four DMRS symbolsthat are located in pairs of symbols with different pairs spread acrossthe subframe, and a fourth DMRS pattern 620 with two spaced DMRSsymbols. In cases where a two-symbol uplink burst is present, a fifthDMRS pattern 625 may include three spaced DMRS symbols, a sixth DMRSpattern 630 with two spaced DMRS symbols, and a seventh DMRS pattern 635with two front-loaded DMRS symbols and a third spaced DMRS symbol.

In cases where a three-symbol uplink burst is present, an eighth DMRSpattern 640 may include three spaced DMRS symbols, a ninth DMRS pattern645 may include two spaced DMRS symbols, and a tenth DMRS pattern 650may include four DMRS symbols arranged as pairs of adjacent DMRS symbolswith different pairs spread across the downlink symbols. In cases wherea five-symbol uplink burst is present, an eleventh DMRS pattern 655 mayhave two spaced DMRS symbols spread across the downlink symbols.

As indicated above, various techniques discussed herein provide formapping one or more DMRS patterns to one or more available CSI-RSresources. In some cases, a base station may transmit DMRS patterns anda mapping between DMRS patterns and CSI-RS resources to a UE, andsubsequently transmit (e.g., in downlink control information (DCI) orradio resource control (RRC) signaling) an indication of a DMRS patternand an indication of a selected CSI-RS resource (e.g., an indication ofthe CSI-RS resource or an index to a set of CSI-RS resources provided inthe mapping) used for one or more transmissions. A UE may use the DMRSpattern, the indication of the selected CSI-RS resource, and themapping, to determine CSI-RS resources. In some other cases, the basestation may transmit a CSI-RS configuration, and a mapping between DMRSpatterns and CSI-RS resources to a UE. In some aspects, the mapping maybe used to indicate that one or more DMRS patterns may be precluded forDMRS transmissions, based on the CSI-RS configuration. Thus, the UE mayuse the CSI-RS configuration, and the mapping to determine DMRSresources.

In some other cases, the UE may determine an implicit mapping betweenthe DMRS pattern and CSI-RS resources, based on the DMRS patterntransmitted by the base station. For instance, the UE may determine,based on a grant, the DMRS pattern that is to be transmitted and mayimplicitly determine which configured CSI-RS resources may not be usedfor transmission of CSI-RS. In other cases, the UE may deduce theimplicit mapping based on signaling other than a grant.

In some examples, and as further illustrated in FIG. 6, resourcesselected for CSI-RS and DMRS transmissions may not overlap based on themapping between CSI-RS resources and DMRS patterns. For instance, insome cases, DMRS patterns and CSI-RS resources may overlap byconfiguration, but the mapping may allow non-overlapping resources to beused during scheduling. Thus, in some aspects, one or more DMRSpatterns, or CSI-RS resources may be precluded for RS transmissionsbased on the DCI and mapping (e.g., implicit or explicit).

FIG. 7 illustrates an example of a mapping 700 that supports jointdetermination of demodulation and channel state information referencesignals in accordance with various aspects of the present disclosure. Insome examples, mapping 700 may implement aspects of wirelesscommunication system 100 or 200. In this example, a base station (e.g. abase station 105 of FIG. 1 or 2) may semi-statically signal (e.g.,through RRC signaling) a UE (e.g., a UE 115 of FIG. 1 or 2) a subset ofpossible DMRS patterns/configurations that are likely to be used forthat specific UE. In this example, the base station may signal that DMRSpattern 1 705, DMRS pattern 2 725, DMRS pattern 3 740, or a null DMRSpattern 755, will be used for transmissions with the UE. Other DMRSpatterns may also be indicated, and the example of FIG. 7 is providedfor illustration and discussion purposes with the understanding thatmore of fewer DMRS patterns may be configured at the UE.

The base station may also signal, such as through semi-static signaling(e.g., RRC signaling) the possible CSI-RS resources that may beconfigured to the UE. In this example, for DMRS pattern 1 705, threedifferent CSI-RS resources may be configured to the UE, including CSI-RSresource 1.0 710, CSI-RS resource 1.1 715, and CSI-RS resource 1.2 720.For DMRS pattern 2 725, two different CSI-RS resources may be configuredto the UE, including CSI-RS resource 2.0 730, and CSI-RS resource 2.1735. For DMRS pattern 3 740, two different CSI-RS resources may beconfigured to the UE, including CSI-RS resource 3.0 745, and CSI-RSresource 3.1 750. Similarly, for null DMRS pattern 755, three differentCSI-RS resources may be configured to the UE, including CSI-RS resource0.0 760, CSI-RS resource 0.1 765, and CSI-RS resource 0.2 770.

Such a mapping 700 CSI-RS resources and DMRS configurations providesthat, when a specific DMRS configuration is enabled, only a subset ofthe available CSI-RS resources may be enabled. In some cases, the DMRSpattern and CSI-RS resources may be indicated in DCI provided to a UEfor a particular transmission or set of transmissions. For example, abase station may transmit a first set of bits that indicate which DMRSpattern is used, which may be indexed to a DMRS pattern from the mapping700, along with a second set of bits that indicate the particular CSI-RSresource for the transmission, which may be indexed to the particularCSI-RS resources associated with the signaled DMRS pattern. In someexamples, when no DMRS is transmitted to a UE in a slot, CSI-RS maystill be transmitted in that slot, and the null DMRS pattern 755 may beindicated along with an indication of which of the CSI-RS resource 0.0760, CSI-RS resource 0.1 765, or CSI-RS resource 0.2 770 is used forCSI-RS transmission. In some cases, there may be multiple “Null DMRS”options configured to a UE, so that the base station has the flexibilityto change the DMRS pattern of the other UEs. The “Null DMRS” option maycorrespond to a specified/reference DMRS, such as a front-load DMRSconfiguration, a specified/reference DMRS that may be cell-specificallyconfigured to all the UEs, or combinations thereof. In some cases, oneor more zero power (ZP) CSI-RS resources may be configured to the UEthat may not need to depend on the DMRS configuration, and may beconfigured independently of non-zero-power CSI-RS resources.

As indicated above, in some cases the base station may signal possibleCSI-RS resources that may be configured to a UE. For each CSI-RSresource, depending on the DMRS configurations, some parameters maychange of that specific CSI-RS resource. For example, the same CSI-RSresource may have more than one set of parameters that define it,depending on the DMRS configuration. Such parameters may include, forexample, CSI-RS location (symbols, tones, REs, etc.), CDM options forthe configured ports due to the CSI-RS location change, CSI-RStransmission size, or combinations thereof. For example, a CSI-RSresource may have four symbols and 32 ports. If the configured DMRS is afirst DMRS pattern, then CSI-RS is transmitted in four consecutivesymbols, otherwise if the configured DMRS is a second DMRS pattern,CSI-RS is transmitted in two groups of two adjacent symbols.

FIG. 8 illustrates an example of CSI-RS settings, resource sets, andassociated resources of a mapping 800 that support joint determinationof demodulation and channel state information reference signals inaccordance with various aspects of the present disclosure. In someexamples, mapping 800 may implement aspects of wireless communicationsystem 100 or 200.

In the example of FIG. 8, a CSI-RS setting 805 may have a number ofCSI-RS sets 810 associated therewith, and each CSI-RS set 810 may have anumber of CSI-RS resources 815 associated therewith. In such examples,depending on the DMRS configuration, a different CSI-RS set 810 isenabled, and the CSI-RS resources 815 may be enabled based on the CSI-RSset 810. In some cases, the CSI-RS set 810 may be indicated with a firstset of bits and the CSI-RS resources may be indicated with a second setof bits.

Furthermore, a configured CSI-RS resource (or equivalently theparameters of a CSI-RS resource) may change for different front-loadDMRS configuration (e.g., config-1 or config-2 as discussed above withrespect to FIGS. 3-4). For example, DMRS configuration 1 uses a comb-2solution, whereas DMRS configuration 2 uses a 2-by-2 boxes (FD-OCC andTD-OCC). So, if CSI-RS and DMRS appear on the same symbol, (either NZPor ZP CSIRS), then the CSI-RS pattern may need to change accordingly.

In some other cases, DMRS pattern may change based in part on the CSI-RSand DMRS appearing on the same symbol. For instance, a mapping (eitherimplicit or explicit) between CSI-RS resources and DMRS patternsprovides that, when a specific CSI-RS configuration is enabled, only asubset of the available DMRS patterns may be enabled.

FIG. 9 illustrates an example of DMRS and CSI-RS resources 900 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with various aspects of thepresent disclosure. In some examples, DMRS and CSI-RS resources 900 mayimplement aspects of wireless communication system 100 or 200. In thisexample, a UE may be configured with DMRS pattern 0 905 that includestwo spaced DMRS symbols. In this case, CSI-RS resources may beconfigured to span four OFDM symbols, and may be located around the DMRSsymbols, according to pattern 910. Similarly, DMRS pattern 1 915 mayhave one front-loaded DMRS symbol, and the corresponding DMRS and CSI-RSpattern 920 may have four adjacent OFDM symbols configured for CSI-RS.

FIG. 10 illustrates an example of a DMRS and CSI-RS resources 1000 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with various aspects of thepresent disclosure. In some examples, DMRS and CSI-RS resources 1000 mayimplement aspects of wireless communication system 100 or 200. In thisexample, a first DMRS pattern 1005 may have DMRS resources that use thesame tones in different OFDM symbols. A second DMRS pattern 1010 mayhave DMRS resources that are frequency staggered across OFDM symbols. Insuch cases, CSI-RS resources may be associated with the different DMRSpatterns. Thus, the CSI-RS parameter in such a case would be changedwhen the DMRS configuration changes from the non-staggered to thestaggered configuration.

FIG. 11 illustrates an example of a process flow 1100 that supportsjoint determination of demodulation and channel state informationreference signals in accordance with various aspects of the presentdisclosure. In some examples, process flow 1100 may implement aspects ofwireless communication system 100. Process flow 1100 may include a basestation 105-b, and a UE 115-b, which may be examples of thecorresponding devices described with reference to FIG. 1-2. The basestation 105-b and the UE 115-b may establish a connection 1105 accordingto established connection establishment techniques for the wirelesscommunications system.

At 1110, the base station 105-b may identify DMRS patterns and a set ofavailable CSI-RS resources that may be used for reference signaltransmissions. The DMRS patterns may be identified, for example, as oneor more available DMRS patterns that may be configured at the UE 115-b.The DMRS patterns may be, for example, different patterns of OFDMsymbols that may include DMRS transmissions, a number of adjacent REsthat may be used for DMRS for a particular antenna port, an OCC appliedto adjacent REs, or any combination thereof. In some examples, the basestation 105-b may identify potential DMRS patterns for the UE 115-bbased at least in part on one or more services that may be enabled atthe UE 115-b (e.g., a ultra-reliable low latency (URLLC) or enhancedmobile broadband (eMBB) service) and configurations for uplink anddownlink transmissions associated therewith (e.g., transmissions usingslot TTIs or 1 ms TTIs). CSI-RS resources may be identified based on,for example, a number of symbols that may be available for CSI-RStransmissions, multiplexing available for multiplexing CSI-RS and DMRStransmissions, frequency staggering of DMRS transmissions acrosssymbols, or any combination thereof.

At 1115, the base station 105-b may determine a mapping between the DMRSpatterns and CSI-RS resources for UEs. In some cases, the base stationmay identify a first number of potential DMRS patterns for the UE 115-b,and may then identify a second number of potential CSI-RS resourcesassociated with each DMRS pattern. The base station 105-b may map thepotential CSI-RS resources to the corresponding potential DMRS pattern,and provide the mapping to the UE 115-b through a configuration 1120transmission. In some cases, the configuration 1120 may be transmittedusing RRC signaling, and the potential DMRS patterns and associatedCSI-RS resources may be semi-statically configured at the UE 115-b.

At 1125, the UE 115-b may identify the DMRS patterns and the mapping forthe CSI-RS resources. The UE 115-b may identify the DMRS patterns andthe mapping based on the configuration 1120 transmission. In some cases,the base station 105-b may explicitly indicate each enabled DMRS patternand each of a number of associated CSI-RS resources for each DMRSpattern. In other cases, the UE 115-b may be configured with a supersetof available DMRS patterns and available CSI-RS resources, and theconfiguration 1120 may indicate that one or more subsets of DMRSpatterns, and one or more subsets of CSI-RS resources that areassociated with each DMRS pattern are enabled. In some other cases, theUE 115-b may be configured with a CSI-RS resource configuration, and theconfiguration 1120 may indicate one or more subsets of CSI-RS resourcesthat are enabled.

The base station 105-b may allocate resources for a transmission, andtransmit DCI 1130 to the UE 115-b that contains an indication of theallocated resources. The DCI 1130 may also include information for whichDMRS pattern of the enabled DMRS patterns is to be used for thetransmission, and which CSI-RS resource associated with the selectedDMRS pattern is to be used for the transmission. In some other cases,the DCI 1130 may provide an indication of only one of the CSI-RSresource or DMRS pattern. In such cases, the UE may use an implicitscheme for determining the other one of the DMRS pattern or the CSI-RSresource, respectively.

The UE 115-b, at 1135, may determine the DMRS pattern and the CSI-RSresources based at least in part on the information from the DCI, theenabled DMRS patterns, and the mapping between the DMRS patterns andCSI-RS resources. In some examples, DMRS patterns may be constrained fortransmissions based on the configured CSI-RS resource configuration. Forinstance, the mapping between DMRS patterns and CSI-RS resources may beused to determine one or more DMRS patterns that are precluded, whichmay allow non-overlapping resources to be used for DMRS and CSI-RStransmissions. In such cases, the UE may determine an implicit mappingbetween the DMRS pattern and the CSI-RS resources, based on anindication of one of the DMRS pattern or the CSI-RS resources. In someinstances, the UE 115-b may determine, based on the DCI 1130, theselected CSI-RS resources, and may implicitly determine which DMRSpatterns may not be used for transmission of DMRS. Accordingly, theremay be an implicit association between the DMRS and CSI-RS resources.

In cases where different subsets of CSI-RS resources are associated witha DMRS pattern, the DCI may include an indication of the selected DMRSpattern (e.g., a first index into a list of enabled DMRS patterns) andan indication of the selected CSI-RS resources (e.g., a second indexinto a list of CSI-RS resources associated with the DMRS pattern).

The base station 105-b may then transmit a downlink transmission 1140(e.g., a PDSCH transmission) having associated control, DMRS, and CSI-RStransmissions. At block 1145, the UE 115-b may then receive the DMRS andCSI-RS according to the DMRS pattern and CSI-RS resources that were usedfor the downlink transmission 1140. The UE 115-b may use the DMRS forchannel estimation and coherent demodulation of data transmitted in thedownlink transmission 1140. The UE 115-b may also perform measurementsof the CSI-RS transmissions and may provide such measurements to thebase station 105-b as part of channel state information that may betransmitted to the base station.

FIG. 12 shows a block diagram 1200 of a wireless device 1205 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. Wireless device 1205 may be an example of aspects of a UE115 as described herein. Wireless device 1205 may include receiver 1210,UE communications manager 1215, and transmitter 1220. Wireless device1205 may also include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 1210 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to jointdetermination of demodulation and channel state information referencesignals, etc.). Information may be passed on to other components of thedevice. The receiver 1210 may be an example of aspects of thetransceiver 1535 described with reference to FIG. 15. The receiver 1210may utilize a single antenna or a set of antennas.

UE communications manager 1215 may be an example of aspects of the UEcommunications manager 1515 described with reference to FIG. 15.

UE communications manager 1215 and/or at least some of its varioussub-components may be implemented in hardware, software executed by aprocessor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the UE communicationsmanager 1215 and/or at least some of its various sub-components may beexecuted by a general-purpose processor, a digital signal processor(DSP), an application-specific integrated circuit (ASIC), anfield-programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof, designed to perform the functions described in thepresent disclosure. The UE communications manager 1215 and/or at leastsome of its various sub-components may be physically located at variouspositions, including being distributed such that portions of functionsare implemented at different physical locations by one or more physicaldevices. In some examples, UE communications manager 1215 and/or atleast some of its various sub-components may be a separate and distinctcomponent in accordance with various aspects of the present disclosure.In other examples, UE communications manager 1215 and/or at least someof its various sub-components may be combined with one or more otherhardware components, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with various aspects of the present disclosure.

UE communications manager 1215 may identify a set of DMRS patterns foruse at a UE and a set of available CSI-RS resources, receive downlinkcontrol information (DCI) indicating one or more of the DMRS patternsbased at least in part on a mapping between one or more of the set ofDMRS patterns and one or more of the set of available CSI-RS resourcesthat are associated with the one or more DMRS patterns, and receive oneor more of a DMRS or a CSI-RS based at least in part on the received DCIand the mapping.

Transmitter 1220 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1220 may be collocatedwith a receiver 1210 in a transceiver module. For example, thetransmitter 1220 may be an example of aspects of the transceiver 1535described with reference to FIG. 15. The transmitter 1220 may utilize asingle antenna or a set of antennas.

FIG. 13 shows a block diagram 1300 of a wireless device 1305 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. Wireless device 1305 may be an example of aspects of awireless device 1205 or a UE 115 as described with reference to FIG. 12.Wireless device 1305 may include receiver 1310, UE communicationsmanager 1315, and transmitter 1320. Wireless device 1305 may alsoinclude a processor. Each of these components may be in communicationwith one another (e.g., via one or more buses).

Receiver 1310 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to jointdetermination of demodulation and channel state information referencesignals, etc.). Information may be passed on to other components of thedevice. The receiver 1310 may be an example of aspects of thetransceiver 1535 described with reference to FIG. 15. The receiver 1310may utilize a single antenna or a set of antennas.

UE communications manager 1315 may be an example of aspects of the UEcommunications manager 1515 described with reference to FIG. 15. UEcommunications manager 1315 may also include reference signal manager1325, mapping manager 1330, and reference signal receiver 1335.

Reference signal manager 1325 may identify a set of DMRS patterns foruse at a UE and a set of available CSI-RS resources. Reference signalmanager 1325 may also receive an indication of a first DMRS pattern fora first downlink transmission, and receive an indication of one or moreZP CSI-RS resources that are configured independently of the DMRSpatterns. In some cases, the set of DMRS patterns includes a null DMRSpattern mapped to one or more CSI-RS resources. In some cases, the setof null DMRS patterns are received in a cell-specific configuration ofall UEs within a cell.

Mapping manager 1330 may receive DCI indicating one or more of the DMRSpatterns based at least in part on a mapping between one or more of theset of DMRS patterns and one or more of the set of available CSI-RSresources that are associated with the one or more DMRS patterns. Insome cases, such a mapping may be used by mapping manager 1330 toidentify a first subset of CSI-RS resources that are mapped to the firstDMRS pattern. Alternatively, such a mapping may be used to identify afirst subset of DMRS patterns which may be precluded from DMRStransmissions, based in part on a CSI-RS configuration.

In some cases, mapping manager 1330 may determine first CSI-RS resourcesassociated with the first downlink transmission based on the firstsubset of CSI-RS resources, determine a configuration of the CSI-RSresources based on an associated DMRS pattern, and determine frequencyresources of the CSI-RS resources based on associated DMRS frequencyresources. In some cases, the receiving the mapping further includesreceiving one or more parameters for a same subset of CSI-RS resourcesfor two or more DMRS patterns, at least one of the one or moreparameters being different for different DMRS patterns. In some cases,the one or more parameters include one or more of a CSI-RS location, aCDM configuration for one or more antenna ports, a CSI-RS transmissionsize, or any combination thereof.

Reference signal receiver 1335 may receive one or more of a DMRS orCSI-RS based on the mapping. In some cases, the receiving the one ormore of the DMRS or CSI-RS includes receiving a CSI-RS in a downlinktransmission over the one or more CSI-RS resources mapped to the nullDMRS configuration, and where a DMRS is not received in the downlinktransmission.

Transmitter 1320 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1320 may be collocatedwith a receiver 1310 in a transceiver module. For example, thetransmitter 1320 may be an example of aspects of the transceiver 1535described with reference to FIG. 15. The transmitter 1320 may utilize asingle antenna or a set of antennas.

FIG. 14 shows a block diagram 1400 of a UE communications manager 1415that supports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. The UE communications manager 1415 may be an example ofaspects of a UE communications manager 1215, a UE communications manager1315, or a UE communications manager 1515 described with reference toFIGS. 12, 13, and 15. The UE communications manager 1415 may includereference signal manager 1420, mapping manager 1425, reference signalreceiver 1430, control information manager 1435, and RRC component 1440.Each of these modules may communicate, directly or indirectly, with oneanother (e.g., via one or more buses).

Reference signal manager 1420 may identify a set of DMRS patterns foruse at a UE and a set of available CSI-RS resources. Reference signalmanager 1420 may also receive an indication of a first DMRS pattern fora first downlink transmission, and receive an indication of one or moreZP CSI-RS resources that are configured independently of the DMRSpatterns. In some cases, the set of DMRS patterns includes a null DMRSpattern mapped to one or more CSI-RS resources. In some cases, the setof null DMRS patterns are received in a cell-specific configuration ofall UEs within a cell.

Mapping manager 1425 may receive DCI indicating one or more of the DMRSpatterns based at least in part on a mapping between one or more of theset of DMRS patterns and one or more of the set of available CSI-RSresources that are associated with the one or more DMRS patterns. Insome cases, such a mapping may be used by mapping manager 1425 toidentify a first subset of CSI-RS resources that are mapped to the firstDMRS pattern. Alternatively, such a mapping may be used to identify afirst subset of DMRS patterns which may be precluded from DMRStransmissions, based in part on a CSI-RS configuration.

In some cases, mapping manager 1425 may determine first CSI-RS resourcesassociated with the first downlink transmission based on the firstsubset of CSI-RS resources, determine a configuration of the CSI-RSresources based on an associated DMRS pattern, and determine frequencyresources of the CSI-RS resources based on associated DMRS frequencyresources. In some cases, the receiving the mapping further includesreceiving one or more parameters for a same subset of CSI-RS resourcesfor two or more DMRS patterns, at least one of the one or moreparameters being different for different DMRS patterns. In some cases,the one or more parameters include one or more of a CSI-RS location, aCDM configuration for one or more antenna ports, a CSI-RS transmissionsize, or any combination thereof.

Reference signal receiver 1430 may receive one or more of a DMRS orCSI-RS based on the received DCI and the mapping. In some cases, thereceiving the one or more of the DMRS or CSI-RS includes receiving aCSI-RS in a downlink transmission over the one or more CSI-RS resourcesmapped to the null DMRS configuration, and where a DMRS is not receivedin the downlink transmission.

Control information manager 1435 may receive an indication of the firstCSI-RS resources within the first subset of CSI-RS resources in controlinformation associated with the first downlink transmission. In somecases, the indication of the first CSI-RS resources is receiveddynamically in DCI associated with a downlink transmission.

RRC component 1440 may transmit and receive RRC signaling. In somecases, RRC component 1440 may semi-statically receive configurationinformation including the set of DMRS patterns and the set of availableCSI-RS resources. In some cases, the configuration information isreceived in RRC signaling.

FIG. 15 shows a diagram of a system 1500 including a device 1505 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. Device 1505 may be an example of or include the componentsof wireless device 1205, wireless device 1305, or a UE 115 as describedabove, e.g., with reference to FIGS. 12 and 13. Device 1505 may includecomponents for bi-directional voice and data communications includingcomponents for transmitting and receiving communications, including UEcommunications manager 1515, processor 1520, memory 1525, software 1530,transceiver 1535, antenna 1540, and I/O controller 1545. Thesecomponents may be in electronic communication via one or more buses(e.g., bus 1510). Device 1505 may communicate wirelessly with one ormore base stations 105.

Processor 1520 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a central processing unit (CPU), amicrocontroller, an ASIC, an FPGA, a programmable logic device, adiscrete gate or transistor logic component, a discrete hardwarecomponent, or any combination thereof). In some cases, processor 1520may be configured to operate a memory array using a memory controller.In other cases, a memory controller may be integrated into processor1520. Processor 1520 may be configured to execute computer-readableinstructions stored in a memory to perform various functions (e.g.,functions or tasks supporting joint determination of demodulation andchannel state information reference signals).

Memory 1525 may include random access memory (RAM) and read only memory(ROM). The memory 1525 may store computer-readable, computer-executablesoftware 1530 including instructions that, when executed, cause theprocessor to perform various functions described herein. In some cases,the memory 1525 may contain, among other things, a basic input/outputsystem (BIOS) which may control basic hardware or software operationsuch as the interaction with peripheral components or devices.

Software 1530 may include code to implement aspects of the presentdisclosure, including code to support joint determination ofdemodulation and channel state information reference signals. Software1530 may be stored in a non-transitory computer-readable medium such assystem memory or other memory. In some cases, the software 1530 may notbe directly executable by the processor but may cause a computer (e.g.,when compiled and executed) to perform functions described herein.

Transceiver 1535 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1535 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1535 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1540.However, in some cases, the device may have more than one antenna 1540,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

I/O controller 1545 may manage input and output signals for device 1505.I/O controller 1545 may also manage peripherals not integrated intodevice 1505. In some cases, I/O controller 1545 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 1545 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 1545 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 1545 may be implemented as part of aprocessor. In some cases, a user may interact with device 1505 via I/Ocontroller 1545 or via hardware components controlled by I/O controller1545.

FIG. 16 shows a block diagram 1600 of a wireless device 1605 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. Wireless device 1605 may be an example of aspects of a basestation 105 as described herein. Wireless device 1605 may includereceiver 1610, base station communications manager 1615, and transmitter1620. Wireless device 1605 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 1610 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to jointdetermination of demodulation and channel state information referencesignals, etc.). Information may be passed on to other components of thedevice. The receiver 1610 may be an example of aspects of thetransceiver 1935 described with reference to FIG. 19. The receiver 1610may utilize a single antenna or a set of antennas.

Base station communications manager 1615 may be an example of aspects ofthe base station communications manager 1915 described with reference toFIG. 19.

Base station communications manager 1615 and/or at least some of itsvarious sub-components may be implemented in hardware, software executedby a processor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the base stationcommunications manager 1615 and/or at least some of its varioussub-components may be executed by a general-purpose processor, a DSP, anASIC, an FPGA or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof, designed to perform the functions described in the presentdisclosure.

The base station communications manager 1615 and/or at least some of itsvarious sub-components may be physically located at various positions,including being distributed such that portions of functions areimplemented at different physical locations by one or more physicaldevices. In some examples, base station communications manager 1615and/or at least some of its various sub-components may be a separate anddistinct component in accordance with various aspects of the presentdisclosure. In other examples, base station communications manager 1615and/or at least some of its various sub-components may be combined withone or more other hardware components, including but not limited to anI/O component, a transceiver, a network server, another computingdevice, one or more other components described in the presentdisclosure, or a combination thereof, in accordance with various aspectsof the present disclosure.

Base station communications manager 1615 may identify a set of DMRSpatterns for a UE and a set of available CSI-RS resources for the UE,determine a mapping between one or more of the DMRS patterns and one ormore of the available CSI-RS resources, transmit DCI indicating one ormore of the DMRS patterns based at least in part on the determinedmapping, and transmit one or more of a DMRS or CSI-RS based on thetransmitted DCI and the determined mapping.

Transmitter 1620 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1620 may be collocatedwith a receiver 1610 in a transceiver module. For example, thetransmitter 1620 may be an example of aspects of the transceiver 1935described with reference to FIG. 19. The transmitter 1620 may utilize asingle antenna or a set of antennas.

FIG. 17 shows a block diagram 1700 of a wireless device 1705 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. Wireless device 1705 may be an example of aspects of awireless device 1605 or a base station 105 as described with referenceto FIG. 16. Wireless device 1705 may include receiver 1710, base stationcommunications manager 1715, and transmitter 1720. Wireless device 1705may also include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 1710 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to jointdetermination of demodulation and channel state information referencesignals, etc.). Information may be passed on to other components of thedevice. The receiver 1710 may be an example of aspects of thetransceiver 1935 described with reference to FIG. 19. The receiver 1710may utilize a single antenna or a set of antennas.

Base station communications manager 1715 may be an example of aspects ofthe base station communications manager 1915 described with reference toFIG. 19. Base station communications manager 1715 may also includereference signal manager 1725, mapping manager 1730, and configurationmanager 1735.

Reference signal manager 1725 may identify a set of DMRS patterns for aUE and a set of available CSI-RS resources for the UE, transmit anindication of a first DMRS pattern for a first downlink transmission,transmit an indication of the first CSI-RS resource, and transmit one ormore of a DMRS or CSI-RS based on the transmitted DCI and the determinedmapping. In some cases, reference signal manager 1725 may transmit aCSI-RS in a downlink transmission over the one or more CSI-RS resourcesmapped to a null DMRS pattern, and where a DMRS is not transmitted inthe downlink transmission. In some cases, reference signal manager 1725may determine a configuration of the CSI-RS based on an associated DMRSpattern, and determine frequency resources of the CSI-RS resources basedon associated DMRS frequency resources. In some cases, the set of DMRSpatterns includes a null DMRS pattern mapped to one or more CSI-RSresources. In some cases, the set of DMRS patterns includes a set ofnull DMRS patterns that are configured at a set of UEs in acell-specific configuration.

Mapping manager 1730 may determine a mapping between one or more of theDMRS patterns and one or more of the available CSI-RS resources,identify a first subset of CSI-RS resources that are mapped to the firstDMRS pattern, and select a first CSI-RS resource based on the firstsubset of CSI-RS resources that are mapped to the first DMRS pattern. Insome cases, the determining the mapping between the one or more DMRSpatterns and the subset of the CSI-RS resources further includesconfiguring one or more parameters for a same subset of CSI-RS resourcesfor two or more DMRS patterns, at least one of the one or moreparameters being different for different DMRS patterns. In some cases,the one or more parameters include one or more of a CSI-RS location, aCDM configuration for one or more antenna ports, a CSI-RS transmissionsize, or any combination thereof.

Configuration manager 1735 may transmit DCI indicating one or more ofthe DMRS patterns based at least in part on the determined mapping, andconfigure one or more ZP CSI-RS resources at the UE independently of theDMRS patterns.

Transmitter 1720 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1720 may be collocatedwith a receiver 1710 in a transceiver module. For example, thetransmitter 1720 may be an example of aspects of the transceiver 1935described with reference to FIG. 19. The transmitter 1720 may utilize asingle antenna or a set of antennas.

FIG. 18 shows a block diagram 1800 of a base station communicationsmanager 1815 that supports joint determination of demodulation andchannel state information reference signals in accordance with aspectsof the present disclosure. The base station communications manager 1815may be an example of aspects of a base station communications manager1915 described with reference to FIGS. 16, 17, and 19. The base stationcommunications manager 1815 may include reference signal manager 1820,mapping manager 1825, configuration manager 1830, control informationmanager 1835, and RRC component 1840. Each of these modules maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

Reference signal manager 1820 may identify a set of DMRS patterns for aUE and a set of available CSI-RS resources for the UE, transmit anindication of a first DMRS pattern for a first downlink transmission,transmit an indication of the first CSI-RS resource, and transmit one ormore of a DMRS or CSI-RS based on the transmitted DCI and the determinedmapping. In some cases, reference signal manager 1820 may transmit aCSI-RS in a downlink transmission over the one or more CSI-RS resourcesmapped to a null DMRS pattern, and where a DMRS is not transmitted inthe downlink transmission. In some cases, reference signal manager 1820may determine a configuration of the CSI-RS resources based on anassociated DMRS pattern, and determine frequency resources of the CSI-RSresources based on associated DMRS frequency resources. In some cases,the set of DMRS patterns includes a null DMRS pattern mapped to one ormore CSI-RS resources. In some cases, the set of DMRS patterns includesa set of null DMRS patterns that are configured at a set of UEs in acell-specific configuration.

Mapping manager 1730 may determine a mapping between one or more of theDMRS patterns and one or more of the available CSI-RS resources,identify a first subset of CSI-RS resources that are mapped to the firstDMRS pattern, and select a first CSI-RS resource based on the firstsubset of CSI-RS resources that are mapped to the first DMRS pattern. Insome cases, the determining the mapping between the one or more DMRSpatterns and the subset of the CSI-RS resources further includesconfiguring one or more parameters for a same subset of CSI-RS resourcesfor two or more DMRS patterns, at least one of the one or moreparameters being different for different DMRS patterns. In some cases,the one or more parameters include one or more of a CSI-RS location, aCDM configuration for one or more antenna ports, a CSI-RS transmissionsize, or any combination thereof.

Configuration manager 1830 may transmit DCI indicating one or more ofthe DMRS patterns based at least in part on the determined mapping, andconfigure one or more ZP CSI-RS resources at the UE independently of theDMRS patterns.

Control information manager 1835 may configure and transmit controlinformation to one or more UEs. In some cases, the indication of thefirst CSI-RS resource is transmitted dynamically in DCI associated withthe first downlink transmission.

RRC component 1840 may configure and transmit RRC signaling to one ormore UEs. In some cases, the RRC component 1840 may semi-staticallytransmit in RRC signaling configuration information including the set ofDMRS patterns and the set of available CSI-RS resources.

FIG. 19 shows a diagram of a system 1900 including a device 1905 thatsupports joint determination of demodulation and channel stateinformation reference signals in accordance with aspects of the presentdisclosure. Device 1905 may be an example of or include the componentsof base station 105 as described above, e.g., with reference to FIG. 1.Device 1905 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including base station communications manager 1915,processor 1920, memory 1925, software 1930, transceiver 1935, antenna1940, network communications manager 1945, and inter-stationcommunications manager 1950. These components may be in electroniccommunication via one or more buses (e.g., bus 1910). Device 1905 maycommunicate wirelessly with one or more UEs 115.

Processor 1920 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 1920 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into processor 1920. Processor 1920 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting jointdetermination of demodulation and channel state information referencesignals).

Memory 1925 may include RAM and ROM. The memory 1925 may storecomputer-readable, computer-executable software 1930 includinginstructions that, when executed, cause the processor to perform variousfunctions described herein. In some cases, the memory 1925 may contain,among other things, a BIOS which may control basic hardware or softwareoperation such as the interaction with peripheral components or devices.

Software 1930 may include code to implement aspects of the presentdisclosure, including code to support joint determination ofdemodulation and channel state information reference signals. Software1930 may be stored in a non-transitory computer-readable medium such assystem memory or other memory. In some cases, the software 1930 may notbe directly executable by the processor but may cause a computer (e.g.,when compiled and executed) to perform functions described herein.

Transceiver 1935 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1935 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1935 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1940.However, in some cases the device may have more than one antenna 1940,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

Network communications manager 1945 may manage communications with thecore network (e.g., via one or more wired backhaul links). For example,the network communications manager 1945 may manage the transfer of datacommunications for client devices, such as one or more UEs 115.

Inter-station communications manager 1950 may manage communications withother base station 105, and may include a controller or scheduler forcontrolling communications with UEs 115 in cooperation with other basestations 105. For example, the inter-station communications manager 1950may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, inter-station communications manager1950 may provide an X2 interface within an Long Term Evolution(LTE)/LTE-A wireless communication network technology to providecommunication between base stations 105.

FIG. 20 shows a flowchart illustrating a method 2000 for jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure. Theoperations of method 2000 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method2000 may be performed by a UE communications manager as described withreference to FIGS. 12 through 15. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the UE 115 may perform aspects of the functions described below usingspecial-purpose hardware.

At 2005, the UE 115 may identify a set of DMRS patterns for use at theUE and a set of available CSI-RS resources. The operations at 2005 maybe performed according to the methods described herein. In certainexamples, aspects of the operations at 2005 may be performed by areference signal manager as described with reference to FIGS. 12 through15.

At 2010, the UE 115 may receive DCI indicating one or more of the DMRSpatterns based at least in part on a mapping between one or more of theset of DMRS patterns and one or more of the set of available CSI-RSresources that are associated with the one or more DMRS patterns. Theoperations at 2010 may be performed according to the methods describedherein. In certain examples, aspects of the operations at 2010 may beperformed by a mapping manager as described with reference to FIGS. 12through 15.

At 2015, the UE 115 may receive one or more of a DMRS or CSI-RS based atleast in part on the received DCI and the mapping. The operations at2015 may be performed according to the methods described herein. Incertain examples, aspects of the operations at 2015 may be performed bya reference signal receiver as described with reference to FIGS. 12through 15.

FIG. 21 shows a flowchart illustrating a method 2100 for jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure. Theoperations of method 2100 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method2100 may be performed by a UE communications manager as described withreference to FIGS. 12 through 15. In some examples, a UE 115 may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the UE 115 may perform aspects of the functions described below usingspecial-purpose hardware.

At 2105, the UE 115 may identify a set of DMRS patterns for use at theUE and a set of available CSI-RS resources. The operations at 2105 maybe performed according to the methods described herein. In certainexamples, aspects of the operations at 2105 may be performed by areference signal manager as described with reference to FIGS. 12 through15.

At 2110, the UE 115 may receive DCI indicating one or more of the DMRSpatterns based at least in part on a mapping between one or more of theset of DMRS patterns and one or more of the set of available CSI-RSresources that are associated with the one or more DMRS patterns. Theoperations at 2110 may be performed according to the methods describedherein. In certain examples, aspects of the operations at 2110 may beperformed by a mapping manager as described with reference to FIGS. 12through 15.

At 2115, the UE 115 may receive an indication of a first DMRS patternfor a first downlink transmission. The operations at 2115 may beperformed according to the methods described herein. In certainexamples, aspects of the operations at 2115 may be performed by areference signal manager as described with reference to FIGS. 12 through15.

At 2120, the UE 115 may identify a first subset of CSI-RS resources thatare mapped to the first DMRS pattern. The operations at 2120 may beperformed according to the methods described herein. In certainexamples, aspects of the operations at 2120 may be performed by amapping manager as described with reference to FIGS. 12 through 15.

At 2125, the UE 115 may determine first CSI-RS resources associated withthe first downlink transmission based at least in part on the firstsubset of CSI-RS resources. The operations at 2125 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations at 2125 may be performed by a mapping manager asdescribed with reference to FIGS. 12 through 15.

At 2130, the UE 115 may receive one or more of a DMRS or CSI-RS based atleast in part on the received DCI and the mapping. The operations at2130 may be performed according to the methods described herein. Incertain examples, aspects of the operations at 2130 may be performed bya reference signal receiver as described with reference to FIGS. 12through 15.

FIG. 22 shows a flowchart illustrating a method 2200 for jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure. Theoperations of method 2200 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2200 may be performed by a base station communications manager asdescribed with reference to FIGS. 16 through 19. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the base station 105 may perform aspectsof the functions described below using special-purpose hardware.

At 2205, the base station 105 may identify a set of DMRS patterns for aUE and a set of available CSI-RS resources for the UE. The operations at2205 may be performed according to the methods described herein. Incertain examples, aspects of the operations at 2205 may be performed bya reference signal manager as described with reference to FIGS. 16through 19.

At 2210, the base station 105 may determine a mapping between one ormore of the DMRS patterns and one or more of the available CSI-RSresources. The operations at 2210 may be performed according to themethods described herein. In certain examples, aspects of the operationsat 2210 may be performed by a mapping manager as described withreference to FIGS. 16 through 19.

At 2215, the base station 105 may transmit DCI indicating one or more ofthe DMRS patterns based at least in part on the determined mapping. Theoperations at 2215 may be performed according to the methods describedherein. In certain examples, aspects of the operations at 2215 may beperformed by a configuration manager as described with reference toFIGS. 16 through 19.

At 2220, the base station 105 may transmit one or more of a DMRS orCSI-RS based at least in part on the transmitted DCI and the determinedmapping. The operations at 2220 may be performed according to themethods described herein. In certain examples, aspects of the operationsat 2220 may be performed by a reference signal manager as described withreference to FIGS. 16 through 19.

FIG. 23 shows a flowchart illustrating a method 2300 for jointdetermination of demodulation and channel state information referencesignals in accordance with aspects of the present disclosure. Theoperations of method 2300 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 2300 may be performed by a base station communications manager asdescribed with reference to FIGS. 16 through 19. In some examples, abase station 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the base station 105 may perform aspectsof the functions described below using special-purpose hardware.

At 2305, the base station 105 may identify a set of DMRS patterns for aUE and a set of available CSI-RS resources for the UE. The operations at2305 may be performed according to the methods described herein. Incertain examples, aspects of the operations at 2305 may be performed bya reference signal manager as described with reference to FIGS. 16through 19.

At 2310, the base station 105 may determine a mapping between one ormore of the DMRS patterns and one or more of the available CSI-RSresources. The operations at 2310 may be performed according to themethods described herein. In certain examples, aspects of the operationsat 2310 may be performed by a mapping manager as described withreference to FIGS. 16 through 19.

At 2315, the base station 105 may transmit DCI indicating one or more ofthe DMRS patterns based at least in part on the determined mapping. Theoperations at 2315 may be performed according to the methods describedherein. In certain examples, aspects of the operations at 2315 may beperformed by a configuration manager as described with reference toFIGS. 16 through 19.

At 2320, the base station 105 may transmit an indication of a first DMRSpattern for a first downlink transmission. The operations at 2320 may beperformed according to the methods described herein. In certainexamples, aspects of the operations at 2320 may be performed by areference signal manager as described with reference to FIGS. 16 through19.

At 2325, the base station 105 may identify a first subset of CSI-RSresources that are mapped to the first DMRS pattern. The operations at2325 may be performed according to the methods described herein. Incertain examples, aspects of the operations at 2325 may be performed bya mapping manager as described with reference to FIGS. 16 through 19.

At 2330, the base station 105 may select a first CSI-RS resource basedat least in part on the first subset of CSI-RS resources that are mappedto the first DMRS pattern. The operations at 2330 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations at 2330 may be performed by a mapping manager asdescribed with reference to FIGS. 16 through 19.

At 2335, the base station 105 may transmit an indication of the firstCSI-RS resource. The operations at 2335 may be performed according tothe methods described herein. In certain examples, aspects of theoperations at 2335 may be performed by a reference signal manager asdescribed with reference to FIGS. 16 through 19.

At 2340, the base station 105 may transmit one or more of a DMRS orCSI-RS based at least in part on the transmitted DCI and the determinedmapping. The operations at 2340 may be performed according to themethods described herein. In certain examples, aspects of the operationsat 2340 may be performed by a reference signal manager as described withreference to FIGS. 16 through 19.

It should be noted that the methods described above describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and other systems.A CDMA system may implement a radio technology such as CDMA2000,Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000,IS-95, and IS-856 standards. IS-2000 Releases may be commonly referredto as CDMA2000 1×, 1X, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical andElectronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications System (UMTS). LTE and LTE-A are releases of UMTSthat use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, NR, and GSM aredescribed in documents from the organization named “3rd GenerationPartnership Project” (3GPP). CDMA2000 and UMB are described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). The techniques described herein may be used for the systems andradio technologies mentioned above as well as other systems and radiotechnologies. While aspects of an LTE or an NR system may be describedfor purposes of example, and LTE or NR terminology may be used in muchof the description, the techniques described herein are applicablebeyond LTE or NR applications.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEs115 with service subscriptions with the network provider. A small cellmay be associated with a lower-powered base station 105, as comparedwith a macro cell, and a small cell may operate in the same or different(e.g., licensed, unlicensed, etc.) frequency bands as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 115 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessby UEs 115 having an association with the femto cell (e.g., UEs 115 in aclosed subscriber group (CSG), UEs 115 for users in the home, and thelike). An eNB for a macro cell may be referred to as a macro eNB. An eNBfor a small cell may be referred to as a small cell eNB, a pico eNB, afemto eNB, or a home eNB. An eNB may support one or multiple (e.g., two,three, four, and the like) cells, and may also support communicationsusing one or multiple component carriers.

The wireless communications system 100 or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations 105 may have similar frame timing, andtransmissions from different base stations 105 may be approximatelyaligned in time. For asynchronous operation, the base stations 105 mayhave different frame timing, and transmissions from different basestations 105 may not be aligned in time. The techniques described hereinmay be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), anapplication-specific integrated circuit (ASIC), a field-programmablegate array (FPGA) or other programmable logic device (PLD), discretegate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media maycomprise random-access memory (RAM), read-only memory (ROM),electrically erasable programmable read only memory (EEPROM), flashmemory, compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include CD, laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an exemplary step that is described as “based on conditionA” may be based on both a condition A and a condition B withoutdeparting from the scope of the present disclosure. In other words, asused herein, the phrase “based on” shall be construed in the same manneras the phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication at a userequipment (UE), comprising: semi-statically receiving radio resourcecontrol (RRC) signaling including configuration information indicating aset of DMRS resource patterns and a set of CSI-RS resources, each of theCSI-RS resources being associated with a slot of a plurality of slots;receiving, in a first slot of the plurality of slots, downlink controlinformation (DCI) indicating a first DMRS pattern of the set of DMRSpatterns; and receiving, in the first slot, a DMRS in the first DMRSpattern and a CSI-RS in a first CSI-RS resource associated with thefirst slot based on a mapping between the DMRS patterns of the set ofDMRS patterns and the CSI-RS resources of the set of CSI-RS resources,the mapping precluding overlap between DMRS patterns of the set of DMRSpatterns and CSI-RS resources of the set of CSI-RS resources.
 2. A userequipment (UE), comprising: a processor; memory in electroniccommunication with the processor; and instructions stored in the memoryand operable, when executed by the processor, to cause the apparatus to:semi-statically receive radio resource control (RRC) signaling includingconfiguration information indicating a set of DMRS resource patterns anda set of CSI-RS resources, each of the CSI-RS resources being associatedwith a slot of a plurality of slots; receive, in a first slot of theplurality of slots, downlink control information (DCI) indicating afirst DMRS pattern of the set of DMRS patterns; and receive, in thefirst slot, a DMRS in the first DMRS pattern and a CSI-RS in a firstCSI-RS resource associated with the first slot based on a mappingbetween the DMRS patterns of the set of DMRS patterns and the CSI-RSresources of the set of CSI-RS resources, the mapping precluding overlapbetween DMRS patterns of the set of DMRS patterns and CSI-RS resourcesof the set of CSI-RS resources.
 3. A method for wireless communicationat a base station, comprising: semi-statically transmitting radioresource control (RRC) signaling including configuration informationindicating a set of DMRS resource patterns and a set of CSI-RSresources, each of the CSI-RS resources being associated with arespective slot of a plurality of slots; enabling a first DMRS patternof the set of DMRS patterns for transmission to a user equipment (UE) ina first slot of a plurality of slots; determining a first subset ofCSI-RS resources, of the set of CSI-RS resources, available fortransmission in the first slot based on a mapping between the DMRSpatterns of the set of DMRS patterns and the CSI-RS resources of the setof CSI-RS resources, the mapping precluding overlap between DMRSpatterns of the set of DMRS patterns and CSI-RS resources of the set ofCSI-RS resources; transmitting, in the first slot, downlink controlinformation (DCI) indicating the first DMRS pattern; and transmitting,in the first slot, a DMRS in the first DMRS pattern and a CSI-RS in afirst CSI-RS resource of the first subset of CSI-RS resources.
 4. A basestation, comprising: a processor; memory in electronic communicationwith the processor; and instructions stored in the memory and operable,when executed by the processor, to cause the apparatus to:semi-statically transmit radio resource control (RRC) signalingincluding configuration information indicating a set of DMRS resourcepatterns and a set of CSI-RS resources, each of the CSI-RS resourcesbeing associated with a respective slot of a plurality of slots; enablea first DMRS pattern of the set of DMRS patterns for transmission to auser equipment (UE) in a first slot of a plurality of slots; determine afirst subset of CSI-RS resources, of the set of CSI-RS resources,available for transmission in the first slot based on a mapping betweenthe DMRS patterns of the set of DMRS patterns and the CSI-RS resourcesof the set of CSI-RS resources, the mapping precluding overlap betweenDMRS patterns of the set of DMRS patterns and CSI-RS resources of theset of CSI-RS resources; transmit, in the first slot, downlink controlinformation (DCI) indicating the first DMRS pattern; and transmit, inthe first slot, a DMRS in the first DMRS pattern and a CSI-RS in a firstCSI-RS resource of the first subset of CSI-RS resources.